"I've long maintained that 64 kHz is the ideal sample rate for audio. But I can't get the industry to change."
"48 kHz is considered "pro" sampling rate. The reason for 44.1 kHz on CD's is subject to debate. Some maintain that the sample rate was lowered so that Beethoven's 9th would fit on a single CD. Others claim that it was because that rate was compatible with video equipment. IMO 44.1 kHz is insufficient for professional audio.

Personally I would prefer 64 kHz. Whilst Nyquist theorem is all well and good most people don't understand the details and simply state "the sample rate must be twice the highest desired frequency". The problem with this is as you approach Nyquist the filter demands become extreme. The more extreme the filter demands the more taps are needed, the more precision is needed, the more latency is incurred, etc. A 64 kHz sample rate would give you a nice, smooth roll-off from 20 kHz to 32 kHz rather than the brick wall you get with 44.1 kHz.

There is no hardware advantage to using 48 vs. 44.1. The costs would be the same in either case. Modern converters use over-sampling techniques to implement the necessary anti-aliasing filters thereby reducing off-chip filtering to simple circuits.
MP3s have no native sample rate but are typically 44.1 kHz because they are usually derived from CDs. MP3 is a psycho-acoustic compression format that exploits frequency masking to lower the data required to store audio information."

CD masters were originally made using videotape editing gear and the disk uses Philips' video disk technology that allows replication in a vinyl plant. Only Sony's marketing ever claimed any kind of "perfection" in 44.1k sample rate. Under the hood, it's video!

Arguments about "Nyquist" conveniently ignore the fact that he was assuming infinite slope filters having zero artifacts which exist only in mathematics and not the real world. Minimizing filter artifacts and aliasing within the audible range are the only reasons to use higher sample rates.

Gentle filters produce fewer artifacts however this is at the expense of higher sample rates in order to eliminate aliasing. It's all about the filters and nothing but the filters. Normal digital signal processing involves a great many filters that accumulate artifacts one wants to minimize.

From Cliff @ Fractal Audio:
Some maintain that the sample rate was lowered so that Beethoven's 9th would fit on a single CD. Others claim that it was because that rate was compatible with video equipment. IMO 44.1 kHz is insufficient for professional audio.

Both are true, however the discs became 12cm instead of the original 10cm to fit Beethoven's 9th. The head of Sony was good friends with a conductor at the time, or so the story goes.

44.1 is divisible by the number of lines and frame-rate of the U-matic recorders which were modified for digital audio.